Process and apparatus for repelling spiders in gas appliances

ABSTRACT

A spider repellent device and process to prevent the infestation of spiders in outdoor gas appliances. The repellents include halobenzenes, haloacetophenones, naphthalene, betanaphthylether and camphor. The device is positioned on the gas appliance downstream of the shut-off valve and dispenses the repellent into the area of the gas orifice.

[ 51 May 9,1972

United States Patent Edwards [56] References Cited UNITED STATES PATENTS [54] PROCESS AND APPARATUS FOR REPELLIN G SPIDERS IN GAS APPLIANCES Rounds et a]. ....43i/4 X 12/1967 Frangos. ...........................431/253X [72] Inventor: Monte R. Edwards, Takoma Park, Md.

Assignee:

Primary Examiner-Carroll B. Dority, Jr. Attorney-Mason, Fenwick & Lawrence Washington Gas Light Co., Washington, DC.

[22] Filed: Aug. 3, 1970 ABSTRACT [211 App]. No.:

naphthalene.

20 Claims, 4 Drawing Figures PROCESS AND APPARATUS FOR REPELLING SPIDERS IN GAS APPLIANCES BACKGROUND OF THE INVENTION The present invention relates to a process and device for use in gas appliances. More particularly, the present invention relates to the prevention of spider infestation of gas appliances during non-operational periods for the appliances.

Outdoor gas appliances, particularly gas air-conditioners, but also certain space heaters as well as barbecue grills have been found to malfunction frequently after sustained periods of non-use. It has become apparent that this type of malfunction is frequently not caused by mechanical failure but rather by spiders webbing the gas orifices associated with gas burners during seasons when particular appliances are not functioning.

It has been discovered that spiders of the family Lycosidae including the genera Chiracanthium, Dolomedes and Lycosa are the particularly offensive types which tend to seek refuge in and about the manifold orifice in those gas appliances which are outdoors. The spiders Chiracanthium mildei often, with the advent of cold weather, usually below 40 F, enter the burner box of the gas appliance and hibernate in the orifice of the gas manifold during the cold period. These particular-species spin a thin tight web at either end of the brass spud at the orifice and disrupt, if not completely prevent, the gas flow from the orifice into the gas burner. With the advent of warmer weather, the spiders will molt in this area and then emerge to mate and lay eggs for reproduction.

Experience has shown that the prevalence of the spider infestations is so great in the outdoor gas appliances that the gas utility company has recorded thousands of incidents of infestations causing disruptive gas flow in a single metropolitan area. Such infestations do not only disrupt service to the customer, but are particularly costly to the utility company, since it requires the removal of the spider webs and molts by the servicemen. In one large metropolitan area, it has been recorded that the cost of servicing outdoor gas appliances having disruptive flows from spider infestation has cost over $50,000 each year. With the increase in use of outside gas appliances, particularly air-conditioning units, the losses from spider infestation are rising each year. I

While the fact of spider infestation has been recognized, the solution has been particularly elusive for a number of reasons. Among these, little is known about the life-style of the spider and less about their physical processes which would permit a successful attack upon them to prevent their webs from clogging the orifices. Numerous insecticides and known insect repellents were tested but found to be ineffective, oftentimes for reasons not easily determined. Generally, experiments were conducted to determine what substances the spider would be expected to avoid when presented with a path to an area containing a known concentration of the would-be repellent as compared to a control area.

Even with a repellent that would be found effective for repelling the spider, a commercially usable repellent must meet certain other important criteria for use in a gas appliance. Among these criteria are:

l. The repellent must be effective for a period of at least several years, otherwise no particular advantages in service cost savings would be achieved over the gas appliance without such repellent.

2. The repellent must be compatible with the gas system and particularly be non-corrosive to the gas appliance during nonoperational periods as well as during the period that the gas is being burned. This was a particularly formidable requirement since many of the known insecticides and repellents were found to break down to a corrosive compound when pyrolyzed.

3. The modification of the gas appliance should desirably be kept to a minimum to accept the repellent and should be able to receive the supply of the repellent within the dimensions of the housing of the gas burner.

4. Of course, the very heart of the problem being one of economics, it is necessary that installation, the dispensing device and the repellent all be within a modest cost range.

SUMMARY OF THE INVENTION and which dispenses'continuously'a selected amount .of the repellent into the gas appliance. A tubular spider repellent device designed primarily to be inserted into the pressure tap hole of the manifold will act as a reservoir for the repellent and permit the dispensing of the proper amount of repellent.

OBJECTS OF THE INVENTION The principal object of the present invention is to provide for a gas appliance free of spider infestation during non-operational periods.

It is an object of the present invention to provide a method of providing and dispensing a repellent into the manifold and also the pilot tube of gas appliance to prevent spider infestation.

It is also an object of the present invention to provide an economical and effective method for the dispensing of a spider repellent into the gas appliance.

This invention also has an object, the provision of a spider repellent device containing a particularly effective spider repellent which may be simply and easily dispensed to the existing structure of the gas appliance to effectively avoid the presence of the spiders.

A further object of the present invention is to provide a method and a device for continuously metering and dispensing the proper amount of spider repellent into the gas appliance.

THE DRAWING FIG. 1 is a perspective view, partly broken away, of a gas appliance incorporating the present invention.

FIG. 2 is a side-elevation view, partly broken away, taken along line 2-2 of FIG. 1 illustrating the incorporation of the present invention into the pilot light and the manifold for a gas burner.

FIG.'3 is a view, partly broken away, taken along line 3-3 and illustrating the mounting of the spider repellent device in the manifold and also illustrating the optional porous plug.

FIG. 4 is a view, partly broken away, taken along line 4-4 of FIG. 2 and illustrating the optional incorporation of the spider repellent device in a pilot light tube.

DESCRIPTION OF THE INVENTION As shown in FIG. I, there is illustrated a conventional gas appliance 10 of a type that'may be used for outdoor gas airconditioners and includes a gas supply pipe 12 connected to a suitable source of natural, liquid petroleum gas, or manufactured gas (not shown). Conventional shut-off valve 14 is secured to thegas supply pipe '12 and includes operational handle 16 to operate the valve to open and shut positions. Flow-regulator 18 and adjusting valve 20, conventional in the art, are also illustrated but neither form any part of the present invention. The conventional manifold pipe 22 is secured to the end of the valve 20. The manifold pipe may be of any suitable size, the inside diameter usually ranging from one-fourth to 2 inches depending upon the type of gas appliance and the number of burners to be fed. The end of the manifold pipe 22 is suitably capped as shown at 24.

As shown in FIG. 1, plural gas burners 26 are secured by connecting orifice pipes or tubes 28 which communicate with the gas manifold pipe 22 at 29 as shown best in FIG. 2. Each orifice pipe terminates with a conventional spud 30 secured in the end of the orifice pipe. A gas orifice 32 is provided in the spud to direct the gas flowFlG. 2 also illustrates the typical atmospheric gas burner incorporating the air shutter 34 in the mixing head 36 which is secured to the spud 30 and surrounds the orifice 32. An elongated mixing tube 38, extends to the burner head 40, provided with suitable burner ports 42 and secondary air opening 44. The burners are positioned within a suitable housing 46 which provides coverage and protection for the burners aswell as an exhaust outlet not shown.

As may be seen in FIGS. 1 and 2, a pilot tube 48 extends from and is controlled by the shut-off valve 14 to the burner head 40. The pilot lighttube 48 also includes a gas orifice 50 and the pilot head 52 to produce the pilot light at 53. Suitable gas supply is provided through openings at 54.

It has been found that the spider infestations are primarily, although not exclusively,'in and around the orifice 32 as well as the pilot light orifice 50. The spiders, usually with the advent of the cooler weather, enter the openings or ports in the burner and weave their web around the orifice 32 as well as within the spud 30. The same is true for the pilot light.

To successfully prevent the spider infestation, it has been discovered that the gas appliance may be protected by a spider repellent device best illustratedin FIG. 3. FIG. 4 illustrates a substantially identical device except for the mounting means.

The spider repellent device 56 of FIG. 3 is an elongated tubular member 58 having an end closed as by a suitable cap 62. The means or manner of closing the end of the tubular member 58 forming the spider repellent device 56 is not critical.

The tubularmember is preferably threaded at 64 to fit into the conventional pressure tap hole 66 generally present in the manifold pipe 22. The pressure tap hole 66 is provided in substantially all gas appliances to permit determination of the pressure reaching the burner head 40. Of course if such a tap hole does not exist, a suitable receiving port must be made.

it can be seen that the present invention intends for the spider repellent device to besimply adapted to fit into the pressure tap hole and thus not require any additional apparatus or modifications of the conventional existing gas appliance. It should be manifest that it is not essential that the spider repellent device 56 be secured to the pressure tap hole, it being only important that the interior of the tubular member 58 fluidly communicates with the interior of the manifold pipe 22 as will occur through the open end 68 of the tubular member.

The size of the opening of the end 68 willdetermine, in part, and will meter the amount of the repellent 70 contained within the device'56 that is permitted to enter the manifold pipe 22.

It is contemplated that the end 68 may be narrowed. or made smaller by any suitable metering fluid control means positioned within the end 68. Of course, the inside diameter of the tubular member 58 at the opening 68 will itself have a metering effect. Y

For improved metering control of the repellent 70, it is also contemplated that a porous plug 72 be positioned within the open end 68. The porous plug is particularly useful with highly volatile repellents or normally liquid repellents. 1

The porous plug 72 may be of any suitable non-reactive material such as the metals porous stainless steel, bronze,or various plastics .such as Teflon, polyethylene, polyvinylchloride, etc. It has been found that the porous plug is not critical to the present invention but if used generally should have a mean pore diameter 5-100 microns, which desirably dispenses the repellent at a rate between 0.000l-0.5 mg./hr. in order to provide, a concentration around the gas orifice of approximately 0.000l0.5 mg. per liter. This dispensing rate and concentration are also to be the criteria to be followed if no porous plug is necessary.

Since the problem of spider infestation has been found to occur also with the pilot light, a very similar, spider repellent device is illustrated at 73. The spider repellent device 73 includes similar closed end 60 and cap 62 and a tubular body 58 but need not include the outside thread at 64 as described in connection with device 56. The pilot light repellent device 73 4 7 includes a T-shaped base formed into opposed ferrules 74 and 76 which receive the ends 78 and 80 of the suitable separated pilot light tube 48 as shown in FIG. 4. The tubular body 58 contains the repellent 70. The tubular member includes an open end 68 all as previously described as well as the optional suitably sized porous plug 72.

The repellent 70 has been discovered to be within narrow classes'of substances of many known insecticides or insect repellents. It has been found that the effective repellents for this invention include the halobenzenes having one to three halogens that may be selected from bromine .and chlorine among which paradichlorobenzene has been found to be particularly efi'ective. Mono-, diand tribromo and chloro benzenes are also to be included in this grouping. Other repellants include halo-substituted acetophenones such as the chloroand iodoacetophenones. Naphthalene, betanaphthylether, and camphor are also found to be very useful as spider repellents. Of all of the above, naphthalene, paradichlorobenzene and chloracetophenone are the most effective and of the three, the first two mentioned are the most effective by far.

It is intended that the repellent be filled into the device 56 from whence it may vaporize to the atmosphere within the manifold. The most desirable repellants from the standpoint of ease of handling and dispensing are those that are solid at the temperatures normally encountered in the environment but which may be melted and poured into the tubular member 56. The repellant must also vaporize and if initially a solid at normal atmospheric temperatures, it is desirable to sublimate at a sufficient rate to produce the range of concentration of 0.0001-0.5 mgJliter within the manifold.

When certain rcpellants such as naphthalene and paradiehlobenzene are used as the spider repellents, a porous plug is not required to control thedispensing rate since these repellants sublimate and produce the desired concentration without any porous plug 72. The internal diameter of the opening 68 of the tubular member is usually about one-eighth inch in diameter which effectively meters the flow of the repellant into the manifold. The internal diameter of the opening 68 is not critical and may vary from one-sixteenth inch to l inch or more if desired. The dispensing rate is controllable with the porous plug if desired. For instance, with repellents having a greater vaporization higher than 0.5 mg./hr. and

which' would evaporate to produce concentrations greater than 0.000l-'0.5mg./1 range in the confined area within the gasorifice, a porous plug is essential to reduce the rate of dispensing into the manifold.

1 The amount of the repellent utilized in may vary from 05-20 grams but usually is between 2 and 5 grams and with the vaporization rate as stated above, the spider repellent device should remain efiective for at least several years of continuous dispensing.

As a specific example, the repellent chloracetophenone is placed within a V4 inch tubular member of 3 inch length closed at one end, a porous plug of bronze, having a mean pore opening of 7 microns and a porosity of 47.5 percent is positioned in the other end and screwed into the pressure tap hole. Such a spider repellent device was found in the spring of the year to substantially reduce the spider infestation in outdoor air conditioners when installed for the winder period.

Significantly improved repellent characteristics were obtained when naphthalene and paradichlorobenzene were utilized. Naphthalene was found to reduce by. 60 percent the normal infestation rate while paradichlorobenzene was found to reduce the infestation rate up to about 80 percent. In general, it was found that the average infestation rate without any use of any repellent is about 30 percent based upon inspections made of approximately 9,000 gas air-conditioners. The use of chloracetephenone, as stated above, reduced the infestation rate to about 21.4 percent while naphthalene produced infestation rate of only i 1.8 percent and paradichlorobenzene reduced the infestation rate to 6.3 percent.

the tubular member Tests were also conducted to determine the products of pyrolysis for the repellents within the groups found to be usable and such products were not found to be undesirably corrosive and in fact were considered to be completely without harm to the gas appliance as well as the atmosphere on being exhausted.

From the foregoing, it should be manifest that the objects of the present invention are achieved in a simple and effective manner.

I claim:

1. A gas appliance free from spider infestation during nonoperational periods comprising:

a gas supply pipe,

a gas manifold in fluid communication with and extending from said pipe,

a shut-elf valve connected to said pipe and controlling the flow of gas to said manifold,

gas orifice means positioned along said manifold to provide an outlet for gas to be burned,

a spider-repellent reservoir means containing said repellent positioned downstream from said valve and in fluid communication with said manifold and said gas orifice means fro dispensing said repellent whereby to repel spiders from said gas orifice means and prevent the webbing of the gas orifice means.

2. The gas appliance of claim 1 including spider repellent metering means provided within said reservoir means to control the flow of said repellent out of said reservoir means.

3. The gas appliance of claim 1 including a pilot light tube connected to said gas supply pipe and extending toward said gas orifice means for providing a pilot light proximate to said gas orifice means, said valve controlling the gas flow through said pilot light tube and a second spider repellent reservoir means containing said repellent connected to said pilot light tube downstream from said valve for dispensing said repellent into said pilot light tube whereby to repel spiders from said pilot light tube.

4. The gas appliance of claim 1 including said spider repellent reservoir means being an elongated tubular container secured to the wall of said manifold.

5. The gas appliance of claim 4 wherein said container is a pipe closed at one end and threaded at an open end and said manifold includes a complementary threaded hole in said side wall to permit dispensing of said repellent into said manifold.

6. The gas appliance of claim 1 including said repellent being selected from the group of halobenzenes, haloacetophenones, beta-naphthylethyl-ether, naphthalene and camphor.

7. The gas appliance of claim 2 including said metering means being a porous plug within said reservoir means to permit passage of vaporized repellent into said manifold and said gas orifice means, at a rate of about 0.0001-0.5 ing/hr.

8. The gas appliance of claim 7 including said porous plug being composed of a material having a mean pore diameter of 5-100 microns.

9. The gas appliance of claim 6 including means to meter the repellent at a rate of 0.000 1-0.5 mg./hr.

10. The gas appliance of claim 1 including said repellent being selected from naphthalene, paradichlorobenzene and chloracetophenonc.

11. The gas appliance of claim 10 including said repellent having a vaporization rate of between 0.0001 and 0.5 mgjhr. between a temperature of 0-40" F at atmospheric pressure.

12. The process of repelling spiders from gas orifices downstream from the gas shut-off valve of gas appliances during non-operating periods of said gas appliance comprising:

providing a repellent source in fluid communication with said gas orifice, continuously dispensing said repellent within said gas appliance between said gas orifice and said shut-off valve, whereby to repel spiders from said orifices.

13. The process of claim 12 including controlling the dispensing of said repellent to a rate between 0.0001 and 0.5

m .lhr.

4. The process of claim 12 wherein said repellent is selected from the group of halobenzenes, haloacetophenones, beta-naphthylethyl-ether, naphthalene and camphor.

15. The process of claim 12 wherein said repellent is selected from naphthalene, paradichlorobenzene and chloracetophenone.

16. A spider repellent device for securing to a hole in the manifold of a gas appliance downstream of a shut-ofi valve comprising,

an elongated rigid tubular member having a closed end and an open end, said open end having means to secure said member to said manifold in said hole,

a spider repellent contained within said member to be dispensed from said member into said manifold to prevent spiders from entering said gas appliance.

17. The devices of claim 16 including said spider repellent being selected from the group of halobenzenes, haloacetophenones, beta-naphthylethyl-ether, naphthalene and camphor.

18. The device of claim 16 including said repellent being selected from naphthalene, paradichlorobenzene and chloracetophenone.

19. The device of claim 16 including a metering means provided on said device to control the vaporization of said repellent.

20. The device of claim 19 wherein said metering means is a porous plug having a mean pore diameter of 5-100 microns. 

2. The gas appliance of claim 1 including spider repellent metering means provided within said reservoir means to control the flow of said repellent out of said reservoir means.
 3. The gas appliance of claim 1 including a pilot light tube connected to said gas supply pipe and extending toward said gas orifice means for providing a pilot light proximate to said gas orifice means, said valve controlling the gas flow through said pilot light tube and a second spider repellent reservoir means containing said repellent connected to said pilot light tube downstream from said valve for dispensing said repellent into said pilot light tube whereby to repel spiders from said pilot light tube.
 4. The gas appliance of claim 1 including said spider repellent reservoir means being an elongated tubular container secured to the wall of said manifold.
 5. The gas appliance of claim 4 wherein said container is a pipe closed at one end and threaded at an open end and said manifold includes a complementary threaded hole in said side wall to permit dispensing of said repellent into said manifold.
 6. The gas appliance of claim 1 including said repellent being selected from the group of halobenzenes, haloacetophenones, beta-naphthylethyl-ether, naphthalene and camphor.
 7. The gas appliance of claim 2 including said metering means being a porous plug within said reservoir means to permit passage of vaporized repellent into said manifold and said gas orifice means, at a rate of about 0.0001-0.5 mg./hr.
 8. The gas appliance of claim 7 including said porous plug being composed of a materiAl having a mean pore diameter of 5-100 microns.
 9. The gas appliance of claim 6 including means to meter the repellent at a rate of 0.0001-0.5 mg./hr.
 10. The gas appliance of claim 1 including said repellent being selected from naphthalene, paradichlorobenzene and chloracetophenone.
 11. The gas appliance of claim 10 including said repellent having a vaporization rate of between 0.0001 and 0.5 mg./hr. between a temperature of 0-40* F at atmospheric pressure.
 12. The process of repelling spiders from gas orifices downstream from the gas shut-off valve of gas appliances during non-operating periods of said gas appliance comprising: providing a repellent source in fluid communication with said gas orifice, continuously dispensing said repellent within said gas appliance between said gas orifice and said shut-off valve, whereby to repel spiders from said orifices.
 13. The process of claim 12 including controlling the dispensing of said repellent to a rate between 0.0001 and 0.5 mg./hr.
 14. The process of claim 12 wherein said repellent is selected from the group of halobenzenes, haloacetophenones, beta-naphthylethyl-ether, naphthalene and camphor.
 15. The process of claim 12 wherein said repellent is selected from naphthalene, paradichlorobenzene and chloracetophenone.
 16. A spider repellent device for securing to a hole in the manifold of a gas appliance downstream of a shut-off valve comprising, an elongated rigid tubular member having a closed end and an open end, said open end having means to secure said member to said manifold in said hole, a spider repellent contained within said member to be dispensed from said member into said manifold to prevent spiders from entering said gas appliance.
 17. The devices of claim 16 including said spider repellent being selected from the group of halobenzenes, haloacetophenones, beta-naphthylethyl-ether, naphthalene and camphor.
 18. The device of claim 16 including said repellent being selected from naphthalene, paradichlorobenzene and chloracetophenone.
 19. The device of claim 16 including a metering means provided on said device to control the vaporization of said repellent.
 20. The device of claim 19 wherein said metering means is a porous plug having a mean pore diameter of 5-100 microns. 